Canon 100-400 with 1.4 extender OR Sigma 50-500

Hey all! I am hoping you can help me.

I am looking into buy a Canon 100-400 or Sigma 50-500. I really like the idea of a 500 reach so I am leaning towards the Sigma, but I could get that an a bit more with the 1.4x extender.

So my question is what is better? ;
The Sigma 50-500 or a Canon 100-400 with a 1.4x Extender?

Thanks for the help.

Unless you have a 1d or 1ds/x body or a 5d3 you will be manual focus only if you go canon with extender. You may already know this but if not it may help your decision

I did not know that....it may have made my decision, but I will wait and see what others have to say.

Long slow zooms and tele-converters are not a match made in heaven.

I'd still recommend the 100-400mm over the 50-500mm, but that's personal preference in the lens itself.

If you must have 500mm, then the SIGMA is the way to go.

Yep thats right, currently only 1d series and 5d3 that can AF on lenses that have max aperture f8, anything else will be manual focus.

Also, i would take 100-400mm over sigma 50-500 any day, i used to have sigma 50-500 non os and at 500mm is soft and useless and to be honest i never used it beyond 350mm, so I replaced it with 100-400mm and was very happy. The IQ is much better on 100-400mm even after you crop it than using 500mm on sigma

I second Jake, I'd recommend the 100-400L. I had the Sigma 150-500 OS in the past, which was a pretty good copy, then I purchased a used 100-400L which was a stellar copy. I upsampled the 400mm image from the 100-400L to match the size/field of view of the 500mm image from the Bigmos and it was still sharper than the photo from the Sigma.
I loved my Sigma, don't get me wrong, it introduced me to wildlife photography. However, I consider the 100-400L a little better, based on the copies that I had. AF is better, the Sigma is only about 470mm and not truly 500, sharpness is better, and the Canon is f/5.6 at 400mm. My Sigma had to be stopped down to f/8 to closely match the sharpness of my 100-400L at wide open (500mm and 400mm respecively).
Of course, I know you're talking about the Sigma 50-500 OS, but I just thought I'd share my experience.

I'm glad I got rid of the bigma, dream range but in reality 470mm, not Sharp @ 470mm and you need much light!!

There's no competitor zoom at the moment, as Sigma is making all Canon lenses recently like 35 1.4, maybe one day soon a sharper competitor.
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Ok, so the extender is out, so now it is just lens vs lens...ugh

and yes if I go with the 50-500 it would be the OS version.

My other concern is the nickname for the 100-400 "dust pump"??? Is that bad? I don't know what its called that.

Mjasinski wrote in post #15949981
My other concern is the nickname for the 100-400 "dust pump"??? Is that bad? I don't know what its called that.

Extending the focal length means that air is allowed into the interior of the lens. I've never noticed any dust getting in, but logic tells us it must.

But its an excellent lens and I use it with a 1.4x Kenko PRO 300 converter with good results. I cannot compare it with the Sigma as I've never used that lens.

re "Dust Pump"

The 100-400mm and the SIGMA 400mm and 500mm zooms all extend when zooming out to the long end.

Some smaller zooms (and some larger actually) keep the movement internal, the lens does not physically get longer.

On Any Zoom where the length extends, you are obviously creating a vacuum inside as it extends.

This can contribute to introduced dust.

The 100-400mm "nick name" is a derogatory moniker applied to it by people that mistakenly believe that the reason this can occur is due to the 100-400mm push pull zoom.

In fact, it does not matter how you make the lens longer, pull or twist, the effect is the same.

that said, the 100-400mm faster push pull, makes it actually happen so fast, you can sometimes hear it. But that same fast zooming is what set it apart from twist zooms, it is MUCH faster to use.

I thought I had my mind made up towards the sigma, now I don't know what to do.

I tried a Tamron 200-500 this weekend. It is definitely worth a test drive.

I really want to start at 100 at most, thats why I'm really not even looking at the Sigma 150-500

Either the 100-400L or the Sigma 50-500 OS are a great choice as I currently own both and I honestly cannot tell the difference between the two as far as IQ and sharpness are concerned. Do Not choose the Tamron 200-500 over these two unless you are looking for strictly a very light weight and cheap 500mm tele lens as the auto focus is not even in the ballpark with the Canon and Sigma lenses. I owned the Tamron for over 6 years and mostly shot it in manual focus because the auto focus was too slow to keep up with birds in flight plus it lacks image stabilization so my keeper rate was extremely low (the aperture power diaphragm failed at around 10,000 images). I bought the Sigma 50-500 OS when it was introduced to replace the Sigma 150-500 OS I was currently shooting with at the time because the 150mm was too long on the short end for my preference in an everyday telephoto zoom lens. 6 months later I bought the Canon 100-400L because I shoot a lot of birds in flight and the push/pull zoom of the Canon is much better IMO for locating and then tracking BIF. It would be a tough call for me to have to choose between the Sigma 50-500 OS or the Canon 100-400L but if I had too it would be based on what I planned to shoot mostly. For a general purpose lens for portraits and wildlife (especially BIF) it would be the Canon and the 77mm filter is the same as some of my other lenses. For a multi purpose everyday, travel and wildlife lens I would choose the Sigma for it's 10X focal range and much closer MFD at the shorter focal lengths.